GitLab

Change IPC messages in app_shim_messages to a mojo interface.
- Remove the AppShimMsg_RequestUserAttention method
- Remove the warning that the interface needs versioning

Update how the connection between shim and browser is initialized
- The connection process is initiated in the shim process in the
  AppShimController::CreateChannelAndSendLaunchApp function
- Make the socket created be an AppShimHost interface (the interface
  used to send from the shim to the browser)
- Immediately enqueue a LaunchApp message to the browser process, and
  add an AppShim interface to the LaunchApp method, to allow the
  browser to call back to the shim process
- Update AppShimHost::ServeChannel to bind itself as a AppShimHost
  to the created socket
- Update AppShimHost::LaunchApp to initialize its AppShim pointer.
  Intentionally do not update this method to have a reply, to minimize
  functional changes. Rather, send the reply via the passed AppShim.

Update how channel errors are handled by adding an error callback
to the mojo bindings created in AppShimHost::LaunchApp and
AppShimController::CreateChannelAndSendLaunchApp.

Update unit tests to use the mojo interfaces. Change AppShimHostTest
to use a weak pointer to the AppShimHost, because, when its message
loop is allowed to run, AppShimHost will delete itself on Close.

Remove the comments about requiring that the interface between the
shim and the browser versioned.

Bug: 821651
Change-Id: Ibad84de4ec25d1121e4ef4d8075a20bb3abd8642
Reviewed-on: https://chromium-review.googlesource.com/1103844Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Commit-Queue: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568286}